The present invention relates to disc drive data storage systems and, more particularly, to a disc drive data storage system having a padded slider which resists tipping relative to the disc surface.
Disc drives of the xe2x80x9cWinchesterxe2x80x9d type are well known in the industry. Such drives use rigid discs, which are coated with a magnetizable medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor, which causes the discs to spin and the surfaces of the discs to pass under respective hydrodynamic (e.g. air) bearing disc head sliders. The sliders carry transducers, which write information to and read information from the disc surfaces.
An actuator mechanism moves the sliders from track-to-track across the surfaces of the discs under control of electronic circuitry. The actuator mechanism includes a track accessing arm and a suspension for each head gimbal assembly. The suspension includes a load beam and a gimbal. The load beam provides a load force which forces the slider toward the disc surface. The gimbal is positioned between the slider and the load beam, or is integrated in the load beam, to provide a resilient connection that allows the slider to pitch and roll while following the topography of the disc.
The slider includes a bearing surface, which faces the disc surface. As the disc rotates, the disc drags air under the slider and along the bearing surface in a direction approximately parallel to the tangential velocity of the disc. As the air passes beneath the bearing surface, air compression along the air flow path causes the air pressure between the disc and the bearing surface to increase which creates a hydrodynamic lifting force that counteracts the load force and causes the slider to lift and fly above or in close proximity to the disc surface.
Discs are typically coated with a lubricant to reduce wear at the slider-disc interface. However, the disc lubricant tends to increase the sticking friction (xe2x80x9cstictionxe2x80x9d) between the slider and the disc surface during the start and stop of disc rotation. Sliders are now being proposed that have geometries designed for reducing stiction. For example, discrete raised pads or xe2x80x9cbumpsxe2x80x9d can be fabrication on the bearing surface, which have a small surface area as compared to the bearing surface and provide a slight separation between the bearing surface and the disc surface. This separation can assist the slider in overcoming stiction during contact start/stop (xe2x80x9cCSSxe2x80x9d) operations.
However, these raised pads can increase a tendency of the slider to xe2x80x9ctipxe2x80x9dbackwards under certain operating conditions. Improved slider geometries are desired, which reduce the tendency of the slider to tip backwards.
One aspect of the present invention relates to a disc head slider having a slider body with a leading slider edge, a trailing slider edge, a bearing surface, a back surface, which is opposite to the bearing surface, and a length measured from the leading slider edge to the trailing slider edge. First and second discrete pads extend normally from the bearing surface. The first pad is located forward of a midpoint along the length, and the second pad is located rearward of the midpoint and forward of the slider trailing edge. A recess is formed in the back surface and has a recess floor, which defines a load point surface located between the first and second pads along the length.
Another aspect of the present invention relates to a disc drive suspension assembly, which includes a disc head slider and a suspension. The disc head slider includes a slider body having a leading slider edge, a trailing slider edge, a bearing surface, a back surface, which is opposite to the bearing surface, a length measured from the leading slider edge to the trailing slider edge, and a nominal thickness measured from the back surface to the bearing surface. First and second discrete pads extend normally from the bearing surface. The first pad is located forward of a midpoint along the length, and the second pad is located rearward of the midpoint and forward of the slider trailing edge. The suspension supports the disc head slider and has a load point, which contacts the disc head slider at a location that is between the first and second pads along the length and at a vertical distance from the bearing surface that is less than the nominal thickness.
Yet another aspect of the present invention relates to a disc drive suspension assembly, which includes a suspension having a load point and a slider attached to the suspension for supporting a transducer relative to a disc surface and for receiving a load force through the load point.